Utility and telephony companies bury their fiber optic cables. The exact location of these cables oftentimes becomes uncertain because either the installation records are lost or the above ground landmarks change. This uncertainty presents a problem when these companies or others need to access the cables for upgrades and repairs.
In the prior art, the known methods for locating buried fiber optic cables include post-hole drilling and radio-tone transmission. Not only are these methods costly, the risk in accidentally destroying or damaging the buried cable is high because of exploratory earth drilling. In radio toning, several sparsely-spaced holes are typically dug, resulting in low accuracy and possible position misidentification. Radio toning techniques are also becoming obsolete since cables are being replaced with full dielectrics, as opposed to metal cables, and since the technique cannot reach the distances that are possible in modern fiber span transmission lengths.
It is, accordingly, one object of the invention to provide methods for determining the above-ground proximity to buried optical fiber cables. Another object of the invention is to provide systems and methods for locating buried optical fiber cable, relative to an above ground location, through generation of seismic noises on the ground. Yet another object of the invention is to provide methods and systems for determining the distance to a buried fiber optic cable to an above-ground location in near-real time. Still another object of the invention is to locate submerged fiber cables. These and other objects will be apparent in the description which follows.